Aim: To evaluate clinical effectiveness of diacerein as an adjuvant to diclofenac sodium in treatment of Indian patients with symptomatic osteoarthritis (OA) knee.
Methods: This is a prospective, double-blind, placebo-controlled and intention-to-treat study. An initial washout period of 1 week, was followed by 3 months treatment period during which patients were randomly divided to receive either capsule diacerein 50 mg or matched placebo once daily for the first month and twice daily for the next 2 months with diclofenac sodium 75 mg sustained release tablet once daily given to both groups. Patients were observed for one more month, using paracetamol as rescue therapy. Treatment efficacy was assessed by a visual analogue scale (VAS) and the Western Ontario and McMaster University (WOMAC) Osteoarthritis Index, patient and physician global assessment of OA, daily paracetamol intake.
Results: Of 84 patients screened, 74 patients formed the intent-to-treat population (37 patients in each group). At baseline, both groups were comparable and at the third month functional index and pain intensity were better in the diacerein group (VAS 15.33 ± 5.07; WOMAC 15.9 ± 2.40) as compared to the placebo group (VAS 22.83 ± 6.90;WOMAC 36.8 ± 2.92; P < 0.05). When analyzed at the fourth month, improvement persisted in the iacerein group (VAS 14.83 ± 5.16; WOMAC 16 ± 2.5) as compared to placebo group (VAS 33 ± 7.72; WOMAC 48.26 ± 3.5; P < 0.05), demonstrating the carry-over effect of diacerein, which was confirmed by lesser paracetamol consumption in the diacerein group (5.967 ± 0.8087) as compared to the placebo group (12.433 ± 2.128; P < 0.05).
Conclusion: Use of diacerein and diclofenac sodium together decreases pain and improves joint function significantly more than diclofenac alone in OA knee.